diff --git a/hepcrawl/pipelines.py b/hepcrawl/pipelines.py
index dfc3f1f..1be5ad2 100644
--- a/hepcrawl/pipelines.py
+++ b/hepcrawl/pipelines.py
@@ -101,7 +101,7 @@ def process_item(self, item, spider):
         if 'dois' in item:
             value = [doi['value'] for doi in item['dois']]
             if len(value) > 0:
-                self.logger.info('Processing article.', name=spider.name, doi=value[0])
+                self.logger.info('Processing article.', name=spider.name, doi=str(value[0]))
                 self.dois.append(value)
             else:
                 self.logger.error('Empty DOIs for this article.', name=spider.name)
@@ -273,5 +273,7 @@ def close_spider(self, spider):
                 task_endpoint,
                 kwargs=self._prepare_payload(spider),
             )
-
+            self.logger.info('Spider successfully send payload.', name=spider.name, dois=self.dois, count=self.count)
+        else:
+            self.logger.error('Spider cannot send payload.', name=spider.name, dois=self.dois, count=self.count)
         self._cleanup(spider)